Arthroscopic unicompartmental knee implantation system and related method

ABSTRACT

A knee implantation system for replacing a portion of a knee joint includes an unicondyler tibial implant configured to replace a portion of a tibia that includes a first member and a second member. The first member has a body portion that includes an articulating surface for replacing only a single superior articulating surface of the tibia. The second member has a textured surface. The second member is removably connected to the body portion and the textured surface is disposed about opposite the articulating surface.

FIELD

The present teachings relate to a medical prosthetic and moreparticularly relate to a unicompartmental knee prosthetic system andrelated method.

BACKGROUND

With reference to FIGS. 1 and 2, a human knee joint is shown andgenerally indicated by reference numeral 10. The knee joint 10 includesa femur 12, a tibia 14, a fibula 16 and a patella 18. A myriad ofmedical problems can require partial or complete replacement of one ormore portions of the aforesaid bones. In previous medical procedures,relatively large and complex prosthetics may be passed through one ormore incisions and couple to the respective bones. The prosthetics mayrequire relatively larger incisions and relatively complex manipulationto insert and secure the prosthetics to the bone.

The relatively larger incisions and complex manipulation of theprosthetics may require additional movement and/or cutting of the softtissue surrounding the knee joint 10. The additional movement and/orcutting of the soft tissue may cause longer recovery times andadditional trauma to the knee joint 10.

SUMMARY

The present teachings generally include a knee implantation system forreplacing a portion of a knee joint. The knee implantation systemincludes an unicondyler tibial implant configured to replace a portionof a tibia that includes a first member and a second member. The firstmember has a body portion that includes an articulating surface forreplacing only a single superior articulating surface of the tibia. Thesecond member has a textured surface. The second member is removablyconnected to the body portion and the textured surface is disposed aboutopposite the articulating surface.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present teachings.

FIG. 1 is a prior art front view of a knee joint showing bones, muscletissue and connective tissue of the knee joint.

FIG. 2 is similar to FIG. 1 and shows a patella, associated muscles andconnective tissue partially separated from the respective portions ofthe knee joint.

FIG. 3 is a perspective view of the knee joint, absent the muscle andconnective tissue, showing a lateral condyle and a medial condyle of thefemur and an exemplary incision in accordance with the presentteachings. FIG. 3 also illustrates reference planes with respect to theknee joint.

FIG. 4 is a perspective view of a portion of an exemplaryunicompartmental knee implant system constructed prosthetic inaccordance with the present teachings showing a femoral component and atibial component.

FIG. 5 is a perspective view of the femoral component of FIG. 4 showingbone in-growth holes in a web keel.

FIG. 6 is similar to FIG. 4 and shows a height and a width of a pegrelative to the web keel but does not show bone in-growth holes.

FIG. 7 is similar to FIG. 4 and shows an exploded assembly view of thetibial component including a body portion, a textured surface and bonescrews that can couple to the tibial component in accordance with thepresent teachings.

FIG. 8 is a partial perspective view of the tibial component of FIG. 7showing a locking mechanism having compliant portions.

FIG. 9A is a partial cross-sectional view of a prepared tibial plateaushowing a cannulated driver positioning a cannulated bone screw thereinin accordance with the present teachings.

FIG. 9B is similar to FIG. 9A and shows a portion of the tibialcomponent of FIG. 4 disposed above the cannulated bone screw.

FIG. 9C is similar to FIG. 9B and shows a head of the bone screwspreading apart compliant portions of the locking mechanism as thetibial component is moved toward the tibial plates.

FIG. 9D is similar to FIG. 9C and shows the head of the bone screwcaptured by the locking mechanism thus securing the tibial componentagainst the prepared tibial plateau.

FIG. 10A is similar to FIG. 9D and shows the tibial component coupled toa bone screw without cannulation therethrough in accordance with thepresent teachings. FIG. 10A also shows the configuration of the lockingmechanism relative to the bone screw.

FIG. 10B is similar to FIG. 10A and shows bone in-growth around thetibial component.

FIG. 11A is a partial cross-sectional view of a tibial component securedto a tibial plateau in accordance with another aspect of the presentteachings.

FIG. 11B is similar to FIG. 11A shows bone in-growth around the tibialcomponent.

FIG. 12A is a perspective view of a knee showing a femoral componentsecured to the medial condyle and a tibial component secured to themedial articular surface of the tibia in accordance with the presentteachings.

FIG. 12B is similar to FIG. 12A and shows a femoral component secured tothe lateral condyle and a tibial component implanted over the lateralarticular surface of the tibia.

FIG. 13 is a perspective view of a kit including varying sizes and/orconfigurations of tibial components, femoral component and bone screwsconstructed in accordance with the various aspects of the presentteachings.

FIGS. 14A-14D are cross sectional views of textured surfaces associatedwith tibial components in accordance with the present teachings.

FIGS. 14E-15F are bottom views of textured surfaces associated withtibial components in accordance with the various aspects of the presentteachings.

DETAILED DESCRIPTION

The following description of the various aspects of the presentteachings is merely exemplary in nature and is in no way intended tolimit the teachings. While the various illustrated aspects of thepresent teachings pertain to a knee joint 10 of the human body, it willbe appreciated that the teachings may also be applicable to variousbones of the human body including, but not limited to, the tibia, thefibula, the humerus, the ulna or the radius. It will also be appreciatedthat the teachings may be applicable to various bones of other animals,mammalian or otherwise, requiring replacement with prosthetics due tovarious medical concerns.

With reference to FIG. 4 and in accordance with the present teachings, aunicompartmental knee implantation system 100 generally can include afemoral component 102 and a tibial component 104. The femoral component102 can include a peg 106 and a wall 108 that can intersect, abut and/orbe integrally formed with the peg 106. The wall 108 can include a webkeel 110. The wall 108 can also include a cross-web keel 112, which canbe generally perpendicular to the web keel 110. The peg 106 cangenerally extend from a center 114 of the femoral component 102. Thecross-web keel 112 and a portion of the web keel 110 (i.e., the portionadjacent to the cross-web keel 112) can define the peg 106. In anotheraspect, the wall 108 of the femoral component 102 can intersect and/orabut the peg 106, e.g., a multiple component construction where the peg106 is separate from the wall 108.

The femoral component 102 can be made of a cobalt chrome alloy, one ormore other suitable bio-compatible materials and/or a suitablecombination of materials. The femoral component 102 can also be coated(partially or entirely) in a titanium plasma coating. The titaniumplasma coating can be sputter-coated onto a portion of the (or theentire) femoral component 102. It may be shown that the titanium plasmacoating can create a porous surface on the femoral component 102 thatcan promote bone growth thereto.

With reference to FIG. 5, the web keel 110 and/or the cross-web keel 112can have a web portion 116 that can define one or more holes 118 formed(entirely or partially) therethrough. The holes 118 through the web keel110 and/or the cross-web keel 112 can promote bone growth therethrough(or therein) after the femoral component 102 has been implanted in thefemur 12, as is illustrated in FIGS. 12A and 12B. The plurality of holes118 can be formed as circles, rectangles or other polygonal shapes. Whenthe plurality of holes 118 are not formed entirely through the webportion 116, dimples, depressions, waves and/or other suitablestructures, shapes, configurations, etc. can be formed on the web keel110 and/or the cross-web keel 112. An edge 120 of each of the pluralityof holes 118 can be chamfered, dimpled, scalloped, rounded and/orvarious combinations thereof and, as such, can promote bone growththerethrough (or therein). The titanium plasma coating can be applied onthe web portion 116 (partially or entirely) and/or can be applied nearthe holes 118 and/or the edge 120.

With reference to FIGS. 5 and 6, the web keel 110 can have a dimensionthat can define a height 122 (i.e., H_(wk) shown in FIG. 5) from a rearface 124 of the femoral component 102. The rear face 124 can begenerally opposite an articulating surface 126. The height 122 (H_(WK))of the web keel 110 can vary such that the web keel 110 can be aboutflush (i.e., contoured to join) with the rear face 124 near a posteriorside 128 and/or an anterior side 130 of the femoral component 102. Theheight 122 (H_(WK)) of the web keel 110 adjacent the peg 106 can bealmost equal to a height 132 of the peg 106 (i.e., H_(P) as shown inFIG. 5).

It may be shown that the varying height 122 (H_(WK)) of the web keel 110and/or the relatively little difference between the height 132 (H_(P))of the peg 106 and the height 122 (H_(WK)) of the web keel 110 can beshown to make insertion of the femoral component 102 through theincision 134 (FIG. 3) relatively easier. This may be so because of thepossible reduction of the propensity of catching or hanging up thefemoral component 102 on the incision 134 and/or other medicalequipment, including, but not limited to, an interior surface of acannula.

The height 122 (H_(WK)) of the web keel 110 can be based on the height132 (H_(P)) (FIG. 5) and/or a dimension defining a width 136 (i.e.,W_(P)) (or diameter if applicable) of the peg 106, as shown in FIG. 6. Adimension 138 (i.e., D) can define a difference in a value of the lengthbetween a top 140 of the peg 106 and a top edge 142 of the web keel 110adjacent to the peg 106, i.e., (D), is about equal to (H_(P)) minus(H_(WK)). The dimension 138 (D) can be less than or generally equal tothe width 136 (or diameter) of the peg 106 (W_(P)) (i.e., D about≦W_(P)). In another aspect, the height 122 (H_(WK)) of the web keel 110adjacent to the peg 106 can be greater than or generally equal to avalue of the height 132 (H_(P)) of the peg 106 minus the width 136 (ordiameter) (W_(P)) of the peg 106. In addition, the height 122 (H_(wk))of the web keel 110 adjacent to the peg 106 can be less than orgenerally equal to the height 132 (H_(P)) of the peg 106 (i.e., H_(P)about ≧H_(WK) about ≧H_(P)−H_(WK)).

In further aspects of the present teachings, the height (H_(WK)) of theweb keel 110 can be predetermined by need not based on the height 132(H_(p)) and/or the width 136 (W_(p)) of the peg 106, notwithstanding,the peg 106 can have a varying width, diameter and/or taper. Withreference to FIG. 6, an imaginary plane (P_(WK)) can extend between theposterior side 128 and the anterior side 130 of the femoral component102. The imaginary plane (P_(WK)) can contact the posterior side 128where the rear face 124 and the articulating surface 126 can terminateat a posterior edge (E_(P)). The imaginary plane (P_(WK)) can alsocontact the rear face 124 of the anterior side 130 near an anterior edge(E_(A)). It will be appreciated that the imaginary plane (P_(WK)) cancontact either edge or contact near either edge (E_(P), E_(A)) of thefemoral component 102.

The web keel 110 can extend from the rear face 124 substantially to theimaginary plane (P_(WK)). In this regard, the web keel 110 can abut theimaginary plane (P_(WK)) or can be spaced therefrom to accommodate, forexample, curvature in the web keel 110. As such, the web keel 110 neednot be completely flush with the imaginary plane (P_(WK)). In otheraspects, the peg 106 can extend through the imaginary plane (P_(WK)). Inthis regard, portions of the web keel 110 can be contoured to join thepeg 106 and, therefore, portions of the web keel 110 can extend beyondthe imaginary plane (P_(WK)). The cross-web keel 112 can also extendbeyond the imaginary plane (P_(WK)) and can be contoured to join the peg106.

With reference to FIG. 5, a dimension can define a height 144 of thecross-web keel 112 (i.e., H_(CWK)). The height 144 (H_(CWK)) can be lessthan or generally equal to the height 132 (H_(P)) of the peg 106 (i.e.,H_(CWK) about ≦H_(P)). The top 140 of the peg 106 can be contoured tojoin the web keel 110 and/or the cross-web keel 112. Intersections 146between the web keel 110 and the cross-web keel 112 can be roundedand/or chamfered (i.e., no sharp outside/inside corners and/or roundededges). It may be shown that doing so can reduce the propensity ofcatching or hanging up the femoral component 102 on the incision 134(FIG. 3) and/or other suitable medical equipment (e.g., an interior of acannula.)

A predetermined orientation of the peg 106 relative to the rear face 124(e.g., an angle formed therebetween) can be shown to reduce the catchingor hanging up the femoral component 102 on the incision 134 (FIG. 3)and/or other suitable medical equipment. As such, the peg 106 can extendfrom the rear face 124 in a direction that can be generallyperpendicular to the rear face 124. The peg 106 can also be positionedsuch that an angle 148 (FIG. 5) defined between the peg 106 and the rearface 124 can be less than 90 degrees. The angle 148 of the peg 106relative to the rear face 124 can be varied so that the predeterminedangle can further facilitate compatibility with a native bone structure150 (FIGS. 1-3).

With reference to FIGS. 7 and 8, the tibial component 104 can generallyinclude a first member 152 and a second member 154. The first member 152can generally include an articulating surface 156 (FIGS. 12A and 12B), acircumferential surface 158 and a base surface 160. The base surface 160can be generally opposite the articulating surface 156. The surfaces156, 158, 160 can define a body portion 162. The base surface 160 caninclude one three, four, or more apertures 164 that extend into the bodyportion 162. The base surface 160 can also omit any apertures 164. Thearticulating surface 156 of the tibial component 104 can articulate withthe articulating surface 126 (FIG. 6) of the femoral component 102, asshown in FIGS. 12A and 12B. The articulating surface 156 of the tibialcomponent 104 can also be configured to articulate with the native bonestructure 150, e.g., the femur 12 (FIGS. 1-3).

The second member 154 can include a textured portion 166 that caninclude one or more surfaces. In one example, the second member 154 candefine one or more complementary apertures 168, which can be generallyconcentric with one or more of the apertures 164 formed in the bodyportion 162. A textured portion 166 can define the entire second member154, i.e., generally the entire second member can be textured. Thetextured portion 166 can also be a portion of the second member 154 suchthat one or more portions of the second member 154 can have the texturedportion 166 and the remaining portions of the second member 154 can havea generally planar or smooth appearance.

With reference to FIG. 14E, the textured portion 166 can define a wavysurface. In other aspects, the textured portion 166 can define othersurface configurations and/or combinations thereof discussed in greaterdetail and illustrated in FIGS. 14A-15F. It will be appreciated that thetextured portion 166 can have a single consistent pattern, a singlevarying pattern, a combination of single consistent patterns, acombination of single varying patterns and combinations thereof. Forexample, the textured portion 166 can have a dimension 170 (FIG. 7)defining a distance between crests and the troughs of similarstructures. The dimension 170 between the crests and troughs and/or thedimension between crests (i.e., a pitch) can be constant and/or varyover the textured portion 166.

The first member 152 of the tibial component 104 can be made of amaterial that can be softer than the second member 154 can be. Forexample, the first member 152 can be generally made of ultra-highmolecular weight polyethylene. The second member 154 can be generallymade of titanium. The second member 154 can be partially (or completely)encapsulated by the first member 152 and thus can couple the secondmember 154 to the first member 152. For example, the first member 152can encapsulate the second member 154 such that only the apertures 168are visible (not specifically illustrated). In another example, thefirst member 152 can encapsulate the second member 154 such that thefirst member 152 can encapsulate only a periphery 172 of the secondmember 154 and therefore can expose all or a portion of the texturedportion 166, as shown in FIG. 4 and FIG. 8.

The apertures 164 formed in the body portion 162 of the first member 152can include a compliant locking mechanism 174 in each (or some) of theapertures 164. Each compliant locking mechanism 174 can be used tosecure a ball-head 176 of a bone screw 178 to the tibial component 104.The compliant locking mechanism 174 can include two (or more)semi-annular compliant portions 180 generally opposed from one another.The compliant portions 180 can be spaced from one another and cangenerally define a straight channel 182 therebetween. The complaintportions 180 can also be spaced from walls 184, which can define each ofthe apertures 164, and thus can define an arcuate channel 186 betweenthe complaint portions 180 and the walls 184. In another aspect, asingle compliant portion 180 can be spaced from a portion of the walls184 (not specifically shown).

With reference to FIGS. 7 and 9A, each of the bone screws 178 (or aportion thereof) can be sized to be similar to a dental-sized bone screwand can thus be relatively smaller than typical bone screws used inprevious medical procedures concerning the knee joint 10.

One or more of the bone screws 178 can be cannulated, as shown in FIGS.5A-9B. Each of the cannulated bone screws 178 can include an elongatedchannel formed along (or aligned with) a longitudinal axis L (FIG. 7).The cannulation of bone screws 178 can be shown to assist the medicalpractitioner in inserting the bone screw 178 into a tibial plateau 188,as shown in FIG. 9A. Each of the ball-heads 176 of the bone screws 178can be formed with a generally spherical shape (or other suitablepolygonal shape). The ball-head 176 can be received by a sphericalaccepting cavity 190 (or other suitable and/or complementary polygonalshaped cavities) (FIG. 9B) of the tibial component 104.

Each of the bone screws 178 can also include mechanical threads 192 tosecure the bone screw 178 to the tibial plateau 188. The ball-head 176of each of the bone screws 178 can also include a suitable socket-head194 (FIG. 9B) to accept a driving member 196. The suitable socket-head194 can be formed as a Phillips head, a Torx® head, a square-drive heador other suitable shaped socket-head 194 (FIG. 9D). The longitudinalcannulation 198 (FIG. 9C) can be centered within the socket-head 194, tothus allow a guide wire 200 to be placed through the driving member 196and through the socket-head 194. The driving member 196 can be poweredmanually, electrically, pneumatically, hydraulically and/or by othersuitable methods or combinations thereof that produce torque.

With reference to FIGS. 9C-9D, the semi-annular compliant portions 180can move from a normal condition 202 (i.e., non-deflected) to adeflected condition 204. The ball-head 176 of the bone screw 178 canmove the compliant portions 180 from the normal condition 202 to thedeflected condition 204. The accepting cavity 190 can define the volumebehind the semi-annular compliant portions 180. With reference to FIG.10A, a dimension defining a distance 206 between the semi-annularcompliant portions 180 (i.e., D_(CP)) can be less than a dimensiondefining a diameter 208 (i.e., D_(SP)) between walls 210 of theaccepting cavity 190 (i.e., D_(SP) about >D_(CP)). The accepting cavity190 need not be spherical but can be rectangular (or other suitablepolygonal shaped cavities) and as such, the distance 206 (D_(CP)) can beless than a dimension defining a width between walls of the rectangularportion. In one example, a dimension defining a diameter 212 of theball-head 176 (i.e., D_(BH)) can be less than the diameter 208 (D_(SP))(or applicable width) and can be greater than the distance 206 (D_(CP))(i.e., D_(SP) about >D_(BH) about >D_(CP)).

A length of the bone screw 178 (along the axis L) can be in a range fromabout 8 millimeters to about 13 millimeters (about 0.3 inches to about0.5 inches). In one aspect, a diameter of a shaft can be in a range fromabout 1 millimeter to about 3 millimeters (about 0.04 inches to about0.12 inches). In a further aspect, the diameter of the shaft can beabout 2 mm (about 0.08 inches). The shaft of the bone screws 178 cantaper in the area of the mechanical threads 192. The threadconfiguration can resemble a wood screw thread, other suitable threadconfigurations and combinations thereof. The diameter 212 of theball-head 176 (D_(BH)) can be in a range from about 3 millimeters toabout 4 millimeters (about 0.12 inches to about 0.16 inches).

The tibial component 104 can be secured to the tibial plateau 188 bysnapping the tibial component 104 onto the bone screws 178. Withreference to FIG. 9A, one or more bone screws 178 can be secured to thetibial plateau 188 by, for example, rotating the driver member 196 toinsert the bone screw 178. The guide wire 200 can be inserted throughthe cannulation of the driver member 196 and the bone screw 178. Thedriver member 196 and/or the bone screw 178 can be used without theguide wire 200 or without the cannulation 198. With reference to FIG.9B, the ball-head 176 of the bone screw 178 can be inserted through theaperture 168 on second member 154 of the tibial component 104 and thusinto the compliant locking mechanism 174.

With reference to FIG. 9C, the ball-head 176 can move the compliantlocking portions 180 from the normal condition 202 (FIG. 9B) to thedeflected condition 204 (FIG. 9C). With reference to FIG. 9D, theball-head 176 can move past the compliant locking portions 180 and intothe accepting cavity 190. As the ball-head 176 of the bone screw 178passes the compliant portions 180, the compliant portions 180 can moveback to the normal condition 202 from the deflected condition 204. Whenthe compliant portions 180 move back to the normal condition 202, theball-head 176 can be drawn in and become captured in the acceptingcavity 190 (i.e., a snap fit) and thus can secure the tibial component104 to the tibial plateau 188, as shown in FIGS. 9D and 10A.

With reference to FIG. 10A, the tibial component 104 is illustrated incontact with the tibial plateau 188 shortly after implantation of thetibial component 104. With reference to FIG. 10B, the tibial component104 is shown in contact the tibial plateau 188 after a period in whichthe bone in-growth can occur. With reference to FIGS. 9D, 10A and 10B,the tibial component 104 can be held against the tibial plateau suchthat the tibial component 104 exerts a force on the tibial plateau 188because the snap-fit connection of the ball heads 176 of the bone screws178 to the compliant locking mechanism 174 can generate the force topull the tibial component 104 toward the tibial plateau 188. As areaction to that force, it can be shown that bone in-growth can occuraround the first member 152 and/or the second member 154 of the tibialcomponent 104, as shown in FIG. 10B. With reference to FIG. 10B, thebone in-growth can occur around the textured portion 166, which can beshown to result in new bone filling into the textured portion 166. Itcan be shown that the bone in-growth into or around the textured portion166 can provide a more secure installation relative to a tibialcomponent without the textured portion.

With reference to FIGS. 11A and 11B, an alternative tibial component 214can be formed with a locking rim 216 generally around a periphery 218 ofthe tibial component 214. A complimentary locking rim structure 220 canbe formed in the tibial plateau 188 and can receive the locking rim 216formed on the tibial component 214. The tibial component 214 can includeone or more flanges 222. For example, the tibial component 214 includesa pair of the flanges 222 that are generally opposite each other on thefirst member 222. Each flange 222 can include a protrusion 224 that canengage a groove 226 that can be formed in the tibial plateau 188.

The tibial component 214 can also include a textured portion 228 thatcan be similar to the textured portion 166, as shown in FIGS. 7 and 14.In one example, the textured portion 228 can be recessed into the tibialcomponent 214 such that walls 230 can bound the textured portion 228.The textured portion can also form the bottom (or a portion thereof) ofthe tibial component 214 and, as such, may not recessed.

In one example, the tibial plateau 188 can be configured to accept thetibial component 104 (FIG. 4), the tibial component 214 (FIG. 11A) orthe tibial component 400 (FIG. 15A). Regardless of what is used, themenisci and/or other native materials of the knee joint 10 may need tobe removed or resected from the tibia 14 unless already absent due tomyriad medical concerns. Once the superior articular surfaces 232 (FIG.3) of the tibia 14 are exposed, the tibia 14 can be prepared to acceptthe tibial component 104, 214, 400. It will be appreciated that only themedial superior articular surface or the lateral superior articularsurface need to be prepared to accept the tibial component 104, 214, 400of the unicompartmental knee implantation system 100 in accordance withthe various aspects of the present teachings.

With reference to FIGS. 11A and 11B, the tibia 14 can be prepared toaccept the tibial component 214. An aperture 234 can be formed in thetibia 14 that can have two of the grooves 226 and a raised portion 236.The aperture 234 can be open on one end to permit sliding of the tibialcomponent 214 into the aperture 234 in a direction that can be generallyperpendicular to a longitudinal axis 238 (FIG. 3) of the tibia 14. Theaperture 234 can also be configured to accept the tibial component 214in a direction that can be generally coaxial with the longitudinal axis238 of the tibia 14.

The aperture 234 can define a dimension 240 (i.e., D_(A)) spanning theopening of the aperture 234. The grooves 226 can further expand aportion of the aperture 234 such that a dimension 242 (i.e., D_(G))between the sides 244 of the grooves 226 can be greater than thedimension 240 (D_(A)) (i.e., D_(G) about >D_(A)). Because the grooves226 can further expand a portion of the aperture 234, a lip 246 can bedefined by the aperture 234 and, as such, the dimension 240 (D_(A)) canbe defined by a distance (i.e., the size of the opening) between thelips 246. The raised portion 236 can be sized to fit into the recessedportion of the tibial component 214 and thus can contact the wavyportion 228.

The flanges 222 of the locking rim 216 can be positioned in the grooves226 of the aperture 234 to secure the tibial component 214 to the tibia14. The flanges 222 can be deflected when positioned in the aperture 234(i.e., an implanted position), such that a spring force can be appliedto the lips 246 of the aperture 234 and/or other portions of the tibia14. It may be shown that the spring force further secures the tibialcomponent 214 to the tibia 14. As such, the position of the tibialcomponent 214 causes the textured portion 228 to exert a force on theraised portion 236 and/or other portions of the tibial plateau. It maybe shown that the force exerted on the raised portion 236 and/or otherportions of the tibial plateau may promote bone in-growth into thetextured portion 228.

With reference to FIGS. 15A-15F, the textured portions of the tibialcomponents 400 can be similar to the tibial component 104 but can omitthe apertures 164 and can thus omit the compliant locking mechanisms174. The textured portions 402 will be discussed in further detail. Thetibial component 400 can be secured to the tibial plateau 188 with bonecement and/or other suitable bonding materials.

With reference to FIGS. 3, 12A and 12B, the femoral component 102 and/orthe tibial component 104, 214, 400 can attach to either the medial (FIG.12A) or the lateral (FIG. 12B) condyles of the femur 12 and the tibia14, respectfully. In one example, the inferior end of the femur 12 canbe prepared by resecting a portion of either the medial or lateralcondyles. The portion of the condyle can be further prepared (e.g.,reamed and/or chiseled) to receive the femoral component 102.

With reference to FIGS. 3 and 4, the web keel 110 of the femoralcomponent 102 can be generally aligned with an anterior-posterior plane248 of the femur 12 (FIG. 3). The cross-web keel 112 can be generallyperpendicular to the web keel 110 and thus be generally aligned with amedial-lateral plane 250 of the femur 12. The femoral component 102 canbe inserted in the resected portions of the respective condyles. The peg106, the web keel 110, the cross-web keel 112 or portions thereof can bereceived by an intramedullary canal 252.

With reference to FIG. 3, it will be appreciated that theanterior-posterior plane 248 and the medial-lateral plane 250 are notexactly and specifically located on the body but can provide generalguidance as to orientation and location. As such, alignment of the webkeel 110 (FIG. 4) to the anterior-posterior plane 248 and cross-web keel112 (FIG. 4) to the medial-lateral plane 250 can provide a generalorientation of the femoral component 102 relative to the femur 12.

With reference to FIG. 3, the incision 134 can be a medial parapatellarincision and can be made proximate to the knee joint 10. The incision134 can be of a minimally invasive type, thus the incision 134 can havean overall length of approximately 3 inches to approximately 5 inches(approximately 76 millimeters to approximately 127 millimeters). Theincision (or multiple incisions) can be made at various locations aroundthe knee joint 10 and can aid in insertion of the femoral component 102and/or the tibial component 104. While a minimally invasive incision 136can be used, the femoral component 102 and/or the tibial component 104can be compatible with other incisions and/or other suitable medicalequipment. For example, the tibial component 104 and/or the femoralcomponent 102 can be passed through a cannula and into the incision 134.The configuration of the peg 106, the web keel 110 and/or the cross-webkeel 112, as above-described, may be shown to reduce the propensity ofhanging up or catching on the walls of the cannula.

With reference to FIG. 13, a kit 254 is shown constructed in accordancewith the present teachings. The kit 254 can include a plurality offemoral components 102 having varying peg lengths, diameters,concavities and/or other suitable femoral component configurations. Thekit 254 can also include a plurality of the tibial components 104, 214,400. The tibial components 104, 214, 400 can also include varying sizes,configurations, degree of encapsulation, textured surfaceconfigurations, and number of locking mechanisms formed on the tibialcomponent 104, 214, 400, as applicable. The kit 254 can also include aplurality of bone screws 178 having varying lengths, widths, bone screwthread configurations and cannulated and non-cannulated configurations(not specifically shown).

In one example and with reference to FIGS. 14A-15F, alternativeconfigurations 256 of the textured portion 166, 402 are illustrated inaccordance with the various aspects of the present teachings. Withreference to FIG. 14A, the textured portion 166 can include asquare-wave pattern 258 that can have a top surface 260 (i.e., similarto a crest) and a respective bottom surface 262 (i.e., similar to atrough). The square wave pattern 258 can include a height 264 betweenthe top surface 258 and the bottom surface 260. The top surface 260 caninclude a width 266 and the bottom surface 260 can include a width 268.The height 264, the width 266 and/or the width 268 can be uniform,varied or combinations thereof throughout the textured portion 166.

With reference to FIG. 14B, the textured portion 166 can include a sawtooth pattern 270 that can have a top peak 272 (i.e., similar to acrest) and a respective bottom peak 274 (i.e., similar to a trough). Thesaw tooth wave pattern 270 can include a height 276 between the top peak272 and the bottom peak 274. Two adjacent top peaks can include adistance 278 therebetween and two adjacent bottom peaks 274 can includea distance 280 therebetween. The height 276, the distance 278, and/orthe distance 280 can be uniform, varied, or combinations thereofthroughout the textured portion 166.

With reference to FIG. 14C, the textured portion 166 can include arepeating cylindrical protrusion pattern 282 that can have a top surface284 and a plurality of bottom surfaces 286. The pattern 282 can includea height 288 between the top surface 284 and each bottom surface 286. Apitch 290 can be defined between two of the cylindrical portions 292(i.e., a distance therebetween). The height 288, the pitch 290, theconfiguration of the cylindrical protrusions and combinations thereofcan be uniform, varied, or combinations thereof throughout the texturedportion 166.

With reference to FIG. 14D, the textured portion 166 can include arepeating rectangular protrusion pattern 294 that can have a top surface296 and a respective bottom surface 298. The repeating rectangularpattern 294 can include a height 300 between the top surface 296 and thebottom surface 298. A pitch 302 can be defined between two rectangularportions 304 in the repeating rectangular pattern 294. The height 300,the pitch 302, the configuration of the repeating rectangularprotrusions and/or combinations thereof can be uniform, varied, orcombinations thereof throughout the textured portion 166.

With reference to FIGS. 14E and 15A, the textured portion 166, 402 caninclude a wavy pattern 306, 406. The wavy pattern 306, 406 can include aplurality of wave shaped grooves 308, 408. The wave shaped grooves 308,408 can be parallel to one another, intersect one another and/or bearranged in a random pattern. The apertures 164 can be formed throughthe textured portion 166 and can be omitted from the textured portion402.

With reference to FIGS. 14F and 15B, the textured portion 166, 402 caninclude a diagonal line pattern 310, 410. The diagonal line pattern 310,410 can include a plurality of diagonal grooves 312, 412. The diagonalgrooves 312, 412 can be formed parallel to one another, intersect oneanother, and/or can be formed in a random pattern.

With reference to FIGS. 14G and 15C, the textured portion 166, 402 caninclude a dimple pattern 314, 414. The dimple pattern 314, 414 caninclude a plurality of dimples 316, 416. The dimples 316, 416 can havevarying sizes, varying depths and/or varying shapes. The dimples 316,416 can be arranged in rows and/or columns or also can be arranged in arandom pattern.

With reference to FIGS. 14H and 15D, the textured portion 166, 402 caninclude a radiating line pattern 318, 418. The radiating line pattern318, 418 can include a plurality of radiating grooves 320, 420 from aside 322, 422 of the textured portion 166, 402. The radiating grooves320, 420 can be formed in semi-annular shapes. The width and/orcurvature of the radiating grooves 320, 420 can be uniform and/or randomthroughout portions of the textured portion 166, 402.

With reference to FIGS. 14I and 15E, the textured portion 166, 402 caninclude a mesh pattern 324, 424. The mesh pattern 324, 424 can include afirst set of line members 326, 426 generally perpendicular to a secondset of line members 328, 428 that can form a plurality of wells 330, 430therebetween. It may be shown that the plurality of wells 330, 430promote bone ingrowth and, therefore, may be shown to secure the tibialcomponents 104, 400 to the tibial plateau 188.

With reference to FIGS. 14J and 15F, the textured portion 166, 402 caninclude a plurality of patterns 332, 442. The plurality of patterns 332,442 can include one or more of the above disclosed patterns 306, 406,310, 410, 314, 414, 318, 418, 324, 424. The amount of each of the abovepatterns, the configuration of each pattern and the position of eachpattern relative to another pattern may be uniform, varied or acombination thereof. The configuration of each pattern or theconfiguration of certain patterns relative to other patterns may bebased on the native bone structure.

While specific aspects of the present teachings have been described inthe specification and illustrated in the drawings, it will be understoodby those skilled in the art that various changes may be made andequivalence may be substituted for elements thereof without parting fromthe scope of the present teachings, as defined in the claims.Furthermore, the mixing and matching of features, elements and/orfunctions between various aspects is expressly contemplated herein sothat one skilled in the art would appreciate from the present teachingsthat features, elements and/or functions of one aspect may beincorporated into another aspect of the present teachings asappropriate, unless described otherwise above. Moreover, manymodifications can be made to adapt a particular situation or material tothe present teachings without departing from the scope thereof.Therefore, it is intended that the various aspects of the presentteachings not be limited to the particular examples illustrated by thedrawings and described in the specification as the best mode presentlycontemplated for carrying out the present teachings but that the scopeof the present teachings will include any aspects following within theforegoing description and defined in the appended claims.

1. A knee implantation system for replacing a portion of a knee joint,the knee implantation system comprising: an unicondyler tibial implantconfigured to replace a portion of a tibia, said tibial implantincluding a first member and a second member; said first member having abody portion that includes an articulating surface for replacing only asingle superior articulating surface of the tibia; and said secondmember having a textured surface, said second member is removablyconnected to said body portion and said textured surface is disposedabout opposite said articulating surface.
 2. The knee implantationsystem of claim 1 further comprising at least one locking mechanismformed in said body portion and at least one aperture formed in saidtextured surface, said at least one aperture generally aligned with saidlocking mechanism.
 3. The knee implantation system of claim 2 whereinsaid locking mechanism defines an accepting cavity disposed behind atleast one compliant portion.
 4. The knee implantation system of claim 1further comprising at least one bone screw having a head and a shaft,said head is wider than said shaft, said bone screw operable to coupleto said locking mechanism in said body portion.
 5. The knee implantationsystem of claim 4 wherein a width or a diameter of said head of saidbone screw is in a range from about two millimeters to about fourmillimeters, a diameter of said shaft is about two millimeters and alength of said bone screw is in range of about eight millimeters toabout thirteen millimeters.
 6. The knee implantation system of claim 1wherein said first member at least partially encapsulates said secondmember.
 7. The knee implantation system of claim 1 wherein said texturedsurfaces has a cross-sectional configuration selected from a groupconsisting of wave surface, a square wave pattern, a saw tooth pattern,a cylindrical protrusion pattern, a rectangular protrusion pattern, awavy pattern, a diagonal line pattern, a dimple pattern, radiating linepattern, a mesh pattern, a random pattern and combinations thereof. 8.The knee implantation system of claim 1 further comprising a femoralimplant having an articulating surface and a base surface disposedgenerally opposite said articulating surface of said femoral implant,said articulating surface of said femoral implant operable to articulateabout said articulating surface of said tibial implant and said femoralimplant includes a peg and a wall extending from said base surface,wherein said wall defines a web keel and a cross-web keel extending fromsaid web keel and wherein in at least one of said web keel and saidcross-web keel includes a web portion defining at least one apertureadapted to promote bone in-growth.
 9. The knee implantation system ofclaim 1 further comprising a plurality of unicondyler tibial implantshaving varying sizes of at least one of body portions, textured surfacesand articulating surfaces of said tibial implants
 10. A kneeimplantation system for replacing a portion of a knee joint, the kneeimplantation system comprising: a tibial implant having a body portiondefining an articulating surface; a femoral implant having anarticulating surface and a base surface disposed generally opposite saidarticulating surface of said femoral implant, said articulating surfaceof said femoral implant operable to articulate about said articulatingsurface of said tibial implant, said articulating surface of saidfemoral implant having a anterior side and a posterior side; and a pegand a wall extending from said base surface and an imaginary plane thatextends from said posterior side to said anterior side and intersectssaid peg, said wall extends substantially to said plane.
 11. The kneeimplantation system of claim 10 wherein said wall is generally abutssaid imaginary plane.
 12. The knee implantation system of claim 10wherein a value of a height of said wall adjacent to said peg is greaterthan or equal to a value of a height of said peg minus a value of awidth or diameter of said peg.
 13. The knee implantation system of claim10 wherein said wall defines a web keel and a cross-web keel extendingfrom said web keel, wherein in at least one of said web keel and saidcross-web keel includes a web portion defining at least one apertureadapted to promote bone in-growth.
 14. The knee implantation system ofclaim 12 comprising a plurality of femoral implants having a pluralityof pegs and a plurality of walls, said pegs having varying heights. 15.A knee implantation system for replacing a portion of a knee joint, theknee implantation system comprising: a tibial implant having a firstmember and a second member, said first member having a body portion thatincludes an articulating surface, said second member includes a texturedsurface, wherein said textured surface is disposed generally oppositesaid articulating surface and said textured surface has across-sectional configuration selected from a group consisting of wavesurface, a square wave pattern, a saw tooth pattern, a cylindricalprotrusion pattern, a rectangular protrusion pattern, a wavy pattern, adiagonal line pattern, a dimple pattern, radiating line pattern, a meshpattern, a random pattern and combinations thereof; and a femoralimplant having an articulating surface and a base surface disposedgenerally opposite said articulating surface of said femoral implant,said articulating surface of said femoral implant operable to articulateabout said articulating surface of said tibial implant and said femoralimplant includes a peg and a wall extending from said base surface,wherein said wall defines a web keel and a cross-web keel extending fromsaid web keel and wherein in at least one of said web keel and saidcross-web keel includes a web portion defining at least one apertureadapted to promote bone in-growth.
 16. The knee implantation system ofclaim 15 further comprising at least one locking mechanism defined bysaid body portion, said at least one locking mechanism defines anaccepting cavity disposed behind a first complaint portion and a secondcompliant portion, said accepting cavity having a width or a diametergenerally greater than a distance between said first complaint portionand said second compliant portion.
 17. The knee implantation system ofclaim 16 further comprising at least one bone screw having a head and ashaft, wherein said head of said bone screw has a complementary shape tosaid accepting cavity and wherein a width or a diameter of said head ofsaid bone screw is in a range from about two millimeters to about fourmillimeters, a diameter of said shaft is about two millimeters and alength of said bone screw is in range of about eight millimeters toabout thirteen millimeters.
 18. The knee implantation system of claim 15further comprising at least one flange that extends from said bodyportion having a protrusion that engages the tibia, wherein said firstmember and said second member of said tibial implant are monolithic andat least a portion of said flange is flexible relative and said flangeportion generates a spring force when said protrusion is deflectedtoward said body portion.
 19. The knee implantation system of claim 16comprising a plurality of femoral implants and a plurality of tibialimplants, said femoral implants having a plurality of pegs and aplurality of walls, at least one of said pegs or said walls having atvarying heights, said tibial implants having a plurality of bodyportions, textured surfaces and articulating surfaces, at least one ofsaid body portions, said textured surfaces and said articulatingsurfaces varying in size.
 20. The knee implantation system of claim 15wherein said first member at least partially encapsulates said secondmember of said tibial implant.